Field of the Invention
This invention relates to a surfactant flooding method of recovering petroleum from subterranean petroleum containing formations. More particularly, this invention relates to a method for recovering high asphalt content petroleum which is otherwise not satisfactorily displaced by surfactant flooding, by incorporating a material in the surfactant preflush or surfactant solution which is moderately soluble in water and which is also an effective solvent for the asphaltic petroleum.